1. Field of the Invention
This invention relates to an air bag inflation gas generator to feed combustion gas for inflation of air bags such as air bags for absorbing collision shocks, life jackets, rafts, and escape chutes.
2. Description of the Prior Art
A prior shock absorber to protect a passenger car driver from shocks at collision accidents comprises an air bag and a gas generator to inflate the air bag with gas. At a collision accident of a passenger car, explosives or other gas generating agents having a similar composition thereto, which are charged in the gas generator, are ignited and burnt to produce gas. The air bag is instantaneously inflated by the resultant gas for protecting the driver against any collision shocks, thereby avoiding possible serious injury of the driver.
FIG. 9 shows the air bag inflation gas generator disclosed in Japanese Patent Application Laid-open Print No. 138005/1993. This air bag inflation gas generator comprises a longitudinal outer cylindrical member 13 having a plurality of gas outlets 11 formed in the outer periphery, an inner cylindrical member 17 inserted in the outer cylindrical member 13 and having gas flow openings 15 formed in the outer periphery, a final filter 19 disposed between the outer cylindrical member 13 and the inner cylindrical member 17, a plurality of gas generating agents 23 with a through hole 21 formed at the center accommodated in the stacked state in the axial direction of the inner cylindrical member 17, and an igniter 25 and an ignition agent 27 disposed at one end of the inner cylindrical member 17, wherein the gas generating agents 23 and the ignition agent 27 are accommodated in a gas generating agent pack 29.
With the above air bag inflation gas generator, volume of combustion gas from the gas generating agents 23 can be steeply increased and a large volume of combustion gas can be surely purified.
But, in the above conventional air bag inflation gas generator, since the end of the inner cylindrical member 17 is merely inserted into a hole 13b formed at a bottom 13a of the outer cylindrical member 13, it is difficult to set easily and surely the position of the gas flow openings 15 formed keeping certain positional relation in the inner cylindrical member 17 and the position of the gas outlets 11 formed keeping certain positional relation in the outer cylindrical member 13 in the predetermined positional relation. And, there is a problem that it is difficult to let the combustion gas from the gas generating agents 23 which are burnt inside the inner cylindrical member 17 out from the gas outlets 11 through an optimum route.
More specifically, the combustion gas from the gas generating agents 23 which are burnt inside the inner cylindrical member 17 is flown into the final filter 19 through the gas flow openings 15 of the inner cylindrical member 17, purified in the final filter 19 and flown into an air bag through the gas outlets 11 of the outer cylindrical member 13. But, when the gas flow openings 15 and the gas outlets 11 are not in the predetermined positional relation, the flow-in position of the combustion gas into the final filter 19 and the flow-out position from the final filter 19 are deviated from the set position, and the purifying capacity of the final filter 19 is degraded.